As a sport, yachting may be all about harnessing the power of the wind, but for most superyachts, that's where ecofriendliness ends. Typically, these 45-meter-plus boats guzzle huge amounts of fuel while their owners host lavish parties that require high-powered amenities like air conditioning and fancy sound systems. But the green agenda has begun to reach even these behemoths of the sea, with marine architects and designers seeking ever more innovative ways to apply conservation technologies to their vessels.
When Luciano Benetton's 50-meter Tribù launched in 2007, it became the first private yacht to win the Green Star designation from the Italian classification society RINA. In order to earn the certificate, usually associated with cruise liners and oil tankers, the yacht had to meet a complex list of requirements, including special equipment for treating waste water and rubbish and the elimination of other emissions. (It didn't have to forsake its Jacuzzi, gym, or luxurious kitchen, either.) The Green Star allowed the Tribù access to coveted parts of the world's waterways—such as in Alaska's nature reserves or around Mexico's Yucatán—that require stringent compliance with nonpollution laws (available for charter for €185,000 per week; fraseryachts.com).
But for all its green credentials, the Tribù is still powered by a diesel engine. At last month's annual Monaco Yacht Show, several much more environmentally progressive yachts were on display. Among them: the 58-meter Ethereal—owned by Bill Joy, the inventor of Java and founding engineer of Sun Microsystems—which uses a hybrid electromechanical propulsion system that relies on rechargeable lithium-phosphate batteries. The stored energy allows the yacht to operate silently in "stealth mode" and runs the ship's systems while at anchor, eliminating noise and exhaust. The windows and hatches are designed to control ambient temperature by filtering ultraviolet and infrared light. In line with its ethos, the yacht doesn't come with water skis, but offers ecofriendly gear like kayaks and wakeboards (available for charter for €225,000 per week; camperandnicholsons.com).
Also on display in Monaco was the prototype for a futuristic-looking superyacht that relies solely on solar energy and wind power. The 59-meter Soliloquy, by 23-year-old U.K. design graduate Alastair Callender, will use advanced technology by the Australia-based Solar Sailor Holdings Ltd. in the form of an overhead beam that houses three automated, rigid solar sails, which create a dynamic form that improves the yacht's propulsion (callenderdesigns.co.uk). The superstructure also incorporates a photovoltaic surface, which means that once all the blinds are out of the overhead beam, they offer a sun-collection area of more than 600 square meters. The solar energy is then stored in the yacht's batteries, which can quietly power the on-board electronics. That mean zero emissions for a yacht that can travel at eight knots and requires a smaller crew than a traditional boat. Callender claims the system is so efficient it actually generates more power than it uses. "As you're sitting in the Monaco harbor, you can even give back to the grid the electricity you're not using," he says. "In six hours, the yacht can generate the energy to power a four-bedroom house for eight days."
The 69-meter-long Solar Gem, designed by Dennis Ingemansson, also features a hybrid electric system powered by solar and wind energy, but can cruise much faster, at a maximum speed of 22 knots (dennisingemansson.com). Also in Monaco, Feadship unveiled the 75.6-meter-long Aeon, a green concept yacht with a curvaceous exterior design inspired by the body of a whale shark and a surface largely equipped with solar paneling. Its propulsion is entirely electric, and the yacht runs on synthetic fuel that can be produced from natural gas, biomass, or algae. The engine room contains equipment for converting diesel into hydrogen, and all waste produced from the process—H2O, CO2, and heat—is reused. The hydrogen is then converted to electricity stored in fuel cells. The hybrid system will help the yacht achieve a top speed of 18 knots, which Feadship director Koos Zitman argues could not be achieved yet with solar technology alone.
Some designers are boldly challenging the traditional look of a yacht to increase the area available for solar panels and ultimately improve energy efficiency. At 38 meters wide and 58 meters long, the Wally-Hermes Yacht comes close to resembling a luxury home on the water. The company, a newly formed venture between its two namesakes, claims that the design requires less power at cruising speed than a more traditional-looking boat of equal size. The design incorporates photovoltaic panels covering nearly 900 square meters that can power most of the boat's auxiliary systems. Though the yacht still has a diesel-electric propulsion hybrid engine, like many others, it is pushing in the ecofriendly direction. Who said green yachting had to be an oxymoron?